WO2010038634A1

WO2010038634A1 - Stent delivery system

Info

Publication number: WO2010038634A1
Application number: PCT/JP2009/066448
Authority: WO
Inventors: 杉本　良太; 北岡　孝史
Original assignee: テルモ株式会社
Priority date: 2008-09-30
Filing date: 2009-09-18
Publication date: 2010-04-08
Also published as: EP2322120A1; US20110196472A1; JP5432912B2; EP2322120A4; EP2322120B1; JPWO2010038634A1; CN102098988B; CN102098988A

Abstract

A stent delivery system (1) is provided with a self-expanding stent (10), a shaft section (3) having a guide wire lumen (61), and a sheath (2) having the stent (10) contained in a distal end section thereof. The stent (10) is located at a position which is on the shaft section (3) and near the distal end thereof. The stent delivery system (1) has a wire member (5) and a breaking member (7). The wire member (5) has one end (5a) and the other end (5b) which are fixed to the shaft section (3), and also has an intermediate section (5c) engaged with a proximal end section of the stent (10). The breaking member (7) breaks the wire member (5) to release the stent from the engagement.

Description

Stent delivery system

The present invention relates to a stent delivery system used to improve a stenosis or occlusion occurring in a body lumen such as a blood vessel, a bile duct, a trachea, an esophagus, or a urethra.

In-vivo stents are used to expand the stenosis or occlusion site and secure the lumen to treat various diseases caused by stenosis or occlusion of blood vessels or other in-vivo lumens. In general, it is a tubular medical device.
Hereinafter, a blood vessel will be described as an example, but the present invention is not limited to this.

Since a stent is inserted into the body from outside the body, the diameter of the stent is small at the time of insertion. The stent is expanded at a target stenosis or occlusion site to increase the diameter, and the lumen is held as it is.
As the stent, a metal wire or a cylindrical shape obtained by processing a metal tube is generally used. It is attached to a catheter or the like in a thin state, inserted into a living body, expanded by a certain method at a target site, and tightly fixed to the inner wall of the lumen to maintain the lumen shape. Stents are differentiated between self-expandable and balloon-expandable stents by function and placement method. The balloon-expandable stent does not have an expansion function, and after the stent mounted on the balloon is inserted into the target site, the balloon is expanded, and the stent is expanded (plastically deformed) by the expansion force of the balloon. Fix it in close contact with the inner surface. This type of stent requires the above-described stent expansion operation. On the other hand, a self-expanding stent is a stent that has an expansion function, and is inserted into a living body in a thin and contracted state, and then returns to its original expanded state when released at a target site. The lumen shape is maintained by closely adhering to and fixing.

The purpose of the current stent placement is to return a blood vessel that has been stenotic for some reason to its original patency state, mainly to prevent and reduce restenosis that occurs after procedures such as PTCA. Is almost. In recent years, in order to further suppress the probability of restenosis, drug-eluting stents loaded with drugs such as immunosuppressants and anticancer drugs have been used, and their effects are generally known.
Most of the self-expanding stents are used in peripheral regions such as blood vessels of the lower limbs and the carotid artery, and for example, there are those having a form as shown in Japanese Patent Publication No. 11-505441 (Patent Document 1).

Japanese National Patent Publication No. 11-505441

In a stent delivery system using a self-expanding stent as in Patent Document 1, positioning during placement is difficult compared to a balloon-expandable stent due to the self-expanding property of the stent, and a jumping phenomenon in which the stent jumps out of the expansion device occurs. When this phenomenon occurs, the stent is placed at a position shifted from the planned placement position. Also, during the stent placement procedure, the placement position may need to be readjusted after the stent has been ejected to some extent. However, in Patent Document 1, it is difficult to re-stent the stent into the stent delivery system.

Accordingly, an object of the present invention is a stent delivery system using a self-expanding stent, and when the stent is released from the expansion device, there is no protrusion due to the self-expandability of the stent, and the stent is expanded to some extent. Provided is a stent delivery system that can be accommodated in an expansion device again even after being exposed from the device.

What achieves the above object is as follows.
A stent that is formed in a substantially cylindrical shape, is compressed in the direction of the central axis when inserted into a living body, and expands outward when placed in the living body and can be restored to its original shape before compression; a shaft portion having a guide wire lumen; and the stent And a stent delivery system in which the stent is positioned in the vicinity of the distal end on the shaft portion, and one end portion and the other end portion of the stent delivery system are fixed to the shaft portion. And a stent proximal end fixing wire rod having an intermediate portion anchored at the proximal end portion of the stent, and a fracture member for breaking the stent proximal end portion fixing wire and releasing the anchoring of the stent. Stent delivery system.

FIG. 1 is a partially omitted front view of a stent delivery system according to an embodiment of the present invention. FIG. 2 is a longitudinal sectional view of the stent delivery system shown in FIG. FIG. 3 is a partially omitted front view of the sheath of the stent delivery system shown in FIG. 4 is a partially omitted front view of the shaft portion of the stent delivery system shown in FIG. FIG. 5 is an enlarged vertical sectional view of the vicinity of the distal end portion of the stent delivery system shown in FIG. FIG. 6 is an enlarged longitudinal sectional view of the vicinity of an intermediate portion of the stent delivery system shown in FIG. FIG. 7 is an enlarged longitudinal sectional view of the vicinity of the sheath base end of the stent delivery system shown in FIG. FIG. 8 is an enlarged vertical sectional view of the vicinity of the base end portion of the shaft portion of the stent delivery system shown in FIG. FIG. 9 is an explanatory diagram for explaining the vicinity of the proximal end portion of the stent of the stent delivery system shown in FIG. FIG. 10 is a front view of an example of an indwelling stent used in the stent delivery system of the present invention. FIG. 11 is a developed view of the in-vivo stent of FIG. FIG. 12 is an enlarged view of the vicinity of the proximal end small hole of the stent shown in FIG. FIG. 13 is an enlarged sectional view taken along line AA in FIG. FIG. 14 is an enlarged longitudinal sectional view of the vicinity of the distal end portion of the stent delivery system according to another embodiment of the present invention. FIG. 15 is an enlarged perspective view of the vicinity of the proximal end small hole of the stent used in the stent delivery system of the present invention. FIG. 16 is an explanatory diagram for explaining the operation of the stent delivery system of the present invention. FIG. 17 is an explanatory diagram for explaining the operation of the stent delivery system of the present invention. FIG. 18 is an explanatory diagram for explaining the operation of the stent delivery system of the present invention.

The stent delivery system of the present invention will be described using the following preferred embodiments. In other words, the stent delivery system is a living organ dilator.

The stent delivery system 1 of the present invention is formed in a substantially cylindrical shape, is compressed in the central axis direction when inserted into a living body, expands outward when placed in the living body, and can be restored to a shape before compression, and a guide The stent delivery system includes a shaft portion 3 having a wire lumen 61 and a sheath 2 in which the stent 10 is housed in the distal end portion, and the stent 10 is located near the distal end on the shaft portion 3. Further, the stent delivery system 1 includes a stent base end fixing wire 5 in which one end portion 5a and the other end portion 5b are fixed to the shaft portion 3 and an intermediate portion 5c is anchored to the base end portion of the stent 10, and a stent base It has a breaking member 7 for breaking the end fixing wire 5 and releasing the anchoring of the stent.
In addition, the stent delivery system 1 of the illustrated embodiment includes a stent 10 that can be expanded outwardly during in vivo placement and can be restored to its original shape before compression, a sheath 2 that houses the stent 10 in the distal end portion, and a sheath 2. And a shaft portion 3 through which the stent 10 is slidably inserted and discharged from the distal end of the sheath 2. The stent 10 includes a distal end portion facing the distal end side of the sheath 2 and a proximal end portion facing the proximal end side, and further does not substantially have a bending free end protruding at least at the proximal end side except for the proximal end portion. In this case, the sheath 2 can be re-stored in the sheath 2 by moving the sheath 2 after the tip 2 is exposed. The stent delivery system 1 has a guide wire lumen 61 having one end opened at the distal end of the stent delivery system and the other end opened proximally from the stent housing part of the sheath 2. The shaft portion 3 has one end portion 5 a and the other end portion 5 b fixed to the shaft portion 3, and an intermediate portion 5 c anchored to the proximal end portion of the stent 10, and a stent proximal end portion fixing wire 5. A breaking member 7 for breaking the wire 5 and releasing the anchoring of the stent 10 is provided.

The stent delivery system 1 of the present invention includes a stent 10, a sheath 2 in which the stent 10 is housed in a distal end portion, and a shaft portion 3 through which the sheath 2 is slidably inserted.
As shown in FIGS. 1 to 7, the sheath 2 includes a sheath tube 21 and a sheath hub 22 fixed to the proximal end of the sheath tube 21.
As shown in FIGS. 1 to 7, the sheath tube 21 is a tubular body, and the front end and the rear end are open. The distal end opening functions as a discharge port of the stent 10 when the stent 10 is placed in a stenosis in the body cavity. When the stent 10 is pushed out from the opening of the distal end, the stress load is released and the stent 10 expands and is restored to the shape before compression. The distal end portion of the sheath tube 21 serves as a stent housing portion 21a for housing the stent 10 therein. The sheath tube 21 includes a side hole 23 provided on the proximal end side with respect to the stent housing part 21a. The side hole 23 is for leading the guide wire to the outside.
The outer diameter of the sheath tube 21 is preferably about 0.5 to 4.0 mm, and particularly preferably 0.8 to 2.0 mm. The inner diameter of the sheath tube 21 is preferably about 0.2 to 1.8 mm. The length of the sheath tube 21 is preferably about 300 to 2500 mm, particularly about 300 to 2000 mm.
The material for forming the sheath tube 21 is, for example, polyethylene, polypropylene, nylon, polyethylene terephthalate, PTFE in consideration of physical properties required for the sheath tube (flexibility, hardness, strength, slipperiness, kink resistance, stretchability). Fluorine polymers such as ETFE, and thermoplastic elastomers are preferred. The thermoplastic elastomer is appropriately selected from nylon (for example, polyamide elastomer), urethane (for example, polyurethane elastomer), polyester (for example, polyethylene terephthalate elastomer), and olefin (for example, polyethylene elastomer, polypropylene elastomer). Is done.

Furthermore, it is preferable that the outer surface of the sheath tube 21 is subjected to a treatment for exhibiting lubricity. Examples of such treatment include hydrophilic polymers such as poly (2-hydroxyethyl methacrylate), polyhydroxyethyl acrylate, hydroxypropyl cellulose, methyl vinyl ether maleic anhydride copolymer, polyethylene glycol, polyacrylamide, and polyvinylpyrrolidone. Examples of the method include coating or fixing. Moreover, in order to improve the slidability between the stent 10 and the shaft portion 3 on the inner surface of the sheath tube 21, the above-described ones may be coated or fixed.
A sheath hub 22 is fixed to the proximal end portion of the sheath tube 21 as shown in FIGS. 1 to 3 and FIG. As shown in FIG. 7, the sheath hub 22 includes a seal member 25 that can slide and liquid-tightly hold the shaft portion 3. The sheath hub 22 includes a side port 24.
As a constituent material of the sheath hub 22, a hard or semi-hard material is used. Hard or semi-rigid materials include polycarbonate, polyolefin (eg, polyethylene, polypropylene, ethylene-propylene copolymer), styrenic resin [eg, polystyrene, MS resin (methacrylate-styrene copolymer), MBS resin (methacrylate-butylene- Styrene copolymer)], synthetic resins such as polyester, metals such as stainless steel, aluminum or aluminum alloys can be used.
An elastic material is used as a constituent material of the seal member 25 and an elastic ring 69 described later. Examples of elastic materials include synthetic rubbers such as urethane rubber, silicone rubber, and butadiene rubber, rubbers such as natural rubber such as latex rubber, olefin elastomers (eg, polyethylene elastomer, polypropylene elastomer), polyamide elastomers, and styrene elastomers (eg, , Styrene-butadiene-styrene copolymers, styrene-isoprene-styrene copolymers, styrene-ethylenebutylene-styrene copolymers), synthetic resin elastomers such as polyurethane, urethane elastomers, fluororesin elastomers, and the like.
Reinforcing

members

26 and 27 extending from the distal end of the sheath hub to the distal end side are provided at the distal end of the sheath hub 22.

As shown in FIGS. 1 to 8, the shaft portion 3 is fixed to the shaft main body 33, the distal end tube 31 provided at the distal end of the shaft main body 33 and protruding from the distal end of the sheath 2, and the proximal end portion of the shaft main body 33. A shaft base 30 fixed to the shaft body 33, and a stent base end fixing wire 5 fixed to the shaft main body 33, and a fracture member 7 for breaking the stent base end fixing wire 5 provided on the shaft main body 33. ing.
In this embodiment, the stent proximal end fixing wire 5 is a heat-breakable stent proximal end fixing wire, and the fracture member 7 is a thermal fracture member. The stent proximal end fixing wire 5 and the breaking member 7 are not limited to the above, but the stent is broken from the shaft portion 3 by breaking the stent electrically, mechanically, or hydraulically. It may be.
In this embodiment, the shaft portion 3 is provided with a proximal-side opening of a guide wire lumen that opens at a side portion proximal to the stent housing site of the sheath 2, and the sheath 2 is proximal to the stent housing site. A sheath side hole provided on the side is provided, and a guide wire can be inserted through the sheath side hole and the proximal end side opening.

The tip tube 31 protrudes from the tip of the sheath 2 as shown in FIG. The distal tube 31 is provided with a stopper 32 that prevents the sheath 2 from moving in the distal direction. As shown in FIG. 6, the proximal end portion of the distal tube 31 is curved, enters the side hole 23 of the sheath tube 21, and is detachably engaged. The outer diameter of the distal tube 31 is preferably 0.2 mm to 1.8 mm. Moreover, it is preferable that the front-end | tip part of the front end side stopper 32 is diameter-reduced toward the front end side, as shown in FIG. The outer diameter of the maximum diameter portion of the stopper 32 is preferably 0.5 to 4.0 mm. Moreover, it is preferable that the base end part of the stopper 32 is also diameter-reduced toward the base end side, as shown in FIG. The distal tube 31 has a guide wire lumen 61 extending from the distal end to the proximal end, and the proximal end opening 62 is located 10 to 400 mm proximal from the distal end of the distal tube 31. 50 to 350 mm is particularly preferable. Further, the position of the proximal end opening 62 is preferably about 50 to 250 mm from the rear end of the stent 10 to be disposed (in other words, the rear end of the stent storage site).
The shaft main body 33 has a distal end portion fixed to the proximal end portion of the distal end tube 31, a main body portion extending toward the proximal end side by a predetermined length, and a proximal end portion protruding from the shaft hub 30. . In this embodiment, the shaft body 33 has a distal end portion fixed to the distal tube 31 having a small diameter portion, and the body portion and the proximal end portion have a larger outer diameter than the small diameter portion. It has become. In this embodiment, the distal end portion of the shaft main body 33 is fixed to the side surface of the distal end tube 31 by a heat shrinkable tube 63.
The length of the shaft portion 3 is preferably about 400 to 2500 mm, and particularly preferably 400 to 2200 mm. The outer diameter of the main body of the shaft main body 33 is preferably about 1.0 to 2.5 mm, and particularly preferably 1.0 to 2.0 mm. The length of the tip tube 31 is preferably about 10 to 400 mm, particularly preferably 50 to 350 mm, and the outer diameter is preferably about 0.2 to 2.0 mm. Further, the inner diameter of the lumen 61 is preferably about 0.2 to 2.0 mm, particularly preferably 0.3 to 1.0 mm.

The shaft body 33 may be any solid tube. A coil shaft may also be used. The material for forming the shaft portion 3 is preferably a material having hardness and a certain degree of flexibility. For example, metal wires or metal pipes such as stainless steel and superelastic metal, polyethylene, polypropylene, nylon, polyethylene Fluoropolymers such as terephthalate and ETFE, rod-like bodies such as PEEK (polyether ether ketone) and polyimide, or cyclic bodies can be suitably used. Note that the outer surface of the shaft portion 3 may be coated with a resin having biocompatibility, particularly antithrombogenicity. As the antithrombogenic material, for example, polyhydroxyethyl methacrylate, a copolymer of hydroxyethyl methacrylate and styrene (for example, HEMA-St-HEMA block copolymer) and the like can be preferably used.
Furthermore, it is preferable that the outer surface of the part which may protrude from the sheath 2 among the shaft parts 3 has lubricity. For this purpose, for example, a hydrophilic polymer such as poly (2-hydroxyethyl methacrylate), polyhydroxyethyl acrylate, hydroxypropyl cellulose, methyl vinyl ether maleic anhydride copolymer, polyethylene glycol, polyacrylamide, polyvinylpyrrolidone, or the like is coated, or It may be fixed. Further, the above may be coated or fixed on the entire outer surface of the shaft portion 3. Furthermore, in order to improve the slidability with the guide wire, the above may be coated or fixed on the inner surface of the shaft portion 3.
The shaft body 33 penetrates through the sheath 2 and protrudes from the rear end opening of the sheath 2. As shown in FIGS. 1 to 3 and 8, a shaft hub 30 is fixed to the proximal end portion of the shaft body 33. In this embodiment, a fixing ring 66 is fixed to the shaft body 33 as shown in FIG. Further, a proximal end tube 34 extending from the shaft hub 30 toward the distal end side is fixed to the shaft hub 30. The distal end portion of the proximal end tube 34 is fixed to the fixing ring 66. An elastic ring 69 is fixed to the proximal end of the proximal end tube 34 (inside the shaft hub 30). Furthermore, in this embodiment, a second fixing ring 68 is provided on the distal end side of the predetermined length from the fixing ring 66. An intermediate tube 67 is disposed between the fixing ring 66 and the second fixing ring 68. The intermediate tube 67 is not fixed to any of the shaft main body 33 and the sheath tube 21, and can contact the fixing ring 66 and the second fixing ring 68. By providing such an intermediate tube, the sliding of the sheath becomes good. The intermediate tube 67 preferably has a low friction surface. Specifically, for example, a tube formed of a fluorine-based polymer such as polyethylene, polypropylene, nylon, polyethylene terephthalate, PTFE, ETFE or the like is preferable.

Further, as shown in FIGS. 5 and 9, the distal end portion of the shaft portion 3 (specifically, near the proximal end of the portion where the stent of the distal end tube 31 is disposed) is directed toward the proximal end of the stent 10. The base end side stopper 70 which restricts the movement of is provided. In particular, in this embodiment, the base end side stopper 70 is a spring-like stopper wound around the shaft portion. As shown in FIGS. 5 and 9, the proximal end side stopper 70 includes a proximal end side coil portion 70 a wound around the distal end tube 31, a distal end side extending from the proximal end side coil portion 70 a, and the distal end tube 31. It has the tip side coil part 70b which has a partial non-contact part. The distal end side coil portion 70b of this embodiment is eccentrically fixed to the distal end tube 31, and includes a portion that is separated from a portion that contacts the distal end tube 31. The stent proximal end fixing wire 5 passes through the non-contact portion of the distal end side coil portion 70b with the distal end tube 31. Moreover, the wire 5 of the part extended in the stent direction from the one end part 5a of a wire may be fixed to said front end side coil part 70b. The wire 5 is preferably fixed to the distal end side coil portion 70b by gripping between the coils. Further, the distal end side coil portion 70 b functions as a stopper of the stent 10. Furthermore, as the distal end side coil portion 70b, the distal end tube 31 and the substantially entire portion thereof may be separated as in the embodiment shown in FIG.

Further, the proximal end side coil portion 70a has a spring shape and can be locked without damaging the proximal end portion of the stent. The stopper 70 may be formed of an X-ray contrast material. Thereby, the position near the proximal end of the stent can be grasped under X-ray contrast, and the procedure becomes easier. As the X-ray contrast material, for example, gold, platinum, platinum-iridium alloy, silver, stainless steel, platinum, or alloys thereof are suitable. The stopper 70 is formed by forming a wire with an X-ray contrast material and winding it around the outer surface of the distal tube 31.
Further, as shown in FIGS. 4 to 6 and 9, the shaft portion 3 has one end portion 5 a and the other end portion 5 b fixed to the shaft portion, and an intermediate portion 5 c anchored to the proximal end portion of the stent 10. A heat-breakable stent proximal end fixing wire 5 and a thermally-rupture member 7 for breaking the stent proximal end fixing wire 5 and releasing the anchoring of the stent 10 are provided.
In particular, in this embodiment, as shown in FIG. 9, the stent 10 is provided with a plurality of small holes 18 for inserting a stent proximal end fixing wire provided in the proximal end side coupling portion 16 in a substantially annular shape. Furthermore, the intermediate portion 5c of the stent proximal end fixing wire 5 passes through the plurality of small holes 18 of the stent 10 in order, and as a whole, the plurality of small holes 18 are annularly inserted. It has become. Therefore, the stent 10 is anchored (fixed) to the shaft portion 3 by the stent proximal end portion fixing wire 5 and is not detached from the shaft portion 3 unless the stent proximal end portion fixing wire 5 is broken (cut). It has become a thing.

In particular, in this embodiment, one end portion 5 a of the stent proximal end portion fixing wire 5 is wound around the outer surface of the distal end tube 31 in the vicinity of the stopper 70 and slightly on the proximal end side, and is fixed by the adhesive 51. Yes. The other end 5 b of the stent proximal end fixing wire 5 is wound around and fixed to the outer surface of the shaft body 33. The one end 5a and the other end 5b of the stent proximal end fixing wire 5 are not limited to those wound around the outer surface of the distal tube 31 and the shaft body 33 and fixed. The one end 5a and the other end 5b of the stent proximal end fixing wire 5 may be fixed to the outer surfaces of the distal tube 31 and the shaft body 33 by caulking. Further, in this embodiment, the stent proximal end fixing wire 5 passes through the gap of the coil constituting the spring-like stopper 70 from the one end portion 5a and the other end portion 5b fixed to the shaft portion in the stent direction. It is to be extended. Specifically, the stent proximal end portion fixing wire 5 in the portion extending from the one end portion 5 a and the stent proximal end portion fixing wire 5 in the portion extending from the other end portion 5 b are both of the proximal end side coil portion 70 a of the stopper 70. It passes through the top and extends through between the distal end side coil portion 70b and the distal end tube 31. By forming the stopper in this way, the effect as a stopper of the stent proximal end portion is demonstrated, and by fixing the stent fixing wire, the stent can be securely fixed by the wire. It is possible to prevent tangling of the wire rod to the stent at the time of release from the stent, and to perform the release reliably.

The heat-breakable stent proximal end fixing wire 5 is preferably a thermoplastic resin fiber. The thermoplastic resin is preferably a synthetic resin such as polyethylene, polypropylene, nylon, polyethylene terephthalate, and particularly preferably has a low melting point. Moreover, the heat-breakable stent proximal end fixing wire may be formed of a low melting point resin only in the vicinity of the portion to be thermally broken. Further, the heat-breakable stent proximal end fixing wire may be formed of only a single thermoplastic resin fiber, or a bundle or twist of a plurality of thermoplastic resin fibers. .
The shaft portion 3 includes a thermal fracture member 7 for breaking the stent proximal end fixing wire 5 and releasing the anchoring of the stent 10. In this embodiment, the heat-breaking member 7 includes a heat-generating portion 36 for breakage,

electric cables

64 and 65 having distal ends connected to the heat-generating portions and extending to the base end portion of the shaft body 33, and

electric cables

64 and 65. A connecting portion 35 connected to a power supply device formed at the proximal end portion of the shaft main body 33 is provided. In particular, in this embodiment, the heat-generating portion 36 for breaking the heat-breaking member 7 is fixed to the tip of the shaft body 33, and the

electric cables

64 and 65 are fixed to the outer surface of the shaft body 33. It extends to the base end portion of the main body 33.
A connecting portion 35 for connecting to a power supply (not shown) is formed at the base end portion of the shaft body 33. The connecting portion 35 is formed on the outer surface of the proximal end portion of the shaft body 33 and includes a first electrode portion 37 that is electrically connected to the cable 64 and a second electrode 38 that is connected to the cable 65. In this embodiment, an insulating portion 39 is provided for insulating between the first electrode 37 and the second electrode 38. A part of the heat-breakable stent proximal end fixing wire 5, in this embodiment, a part from the middle part of the predetermined length from the other end part 5 b is encapsulated in the heat-generating part 36 for breaking, Due to the power applied to the first electrode portion 37 and the second electrode 38, the heat generating portion 36 for breaking generates heat, and the heat-breakable stent proximal end portion fixing wire 5 is melted and broken at this portion.

The stent 10 used in the present invention is a so-called self-expandable stent that can be expanded outwardly and restored to its pre-compression shape when placed in vivo. Further, the stent 10 includes a distal end portion facing the distal end side of the sheath 2 and a proximal end portion facing the proximal end side, and further does not substantially have a bending free end protruding at least at the proximal end side except for the proximal end portion. In this case, the sheath 2 can be re-stored in the sheath 2 by moving the sheath 2 after the tip portion is exposed from the sheath 2.
The stent to be used may be one that does not have a free end by coupling the apex of the bent portion on the base end side or the vicinity of the apex to another linear element. Further, the stent used may be as shown in FIGS. 10 and 11. FIG. 10 is a front view of an example of an indwelling stent used in the stent delivery system of the present invention. FIG. 11 is a developed view of the in-vivo stent of FIG.
The stent 10 extends in a predetermined long axis direction while connecting the adjacent wavy struts 13 and 14 that are axially extended from one end side to the other end side of the stent and arranged in the circumferential direction of the stent. One or more connecting struts 15 are provided, and the ends of the wavy struts 13, 14 are coupled to the ends of the adjacent wavy struts.

In particular, the stent 10 shown in FIGS. 10 and 11 includes a plurality of first wavy struts 13 extending in the axial direction from one end side to the other end side of the stent 10 and arranged in the circumferential direction of the stent, and the first wavy struts 13. A plurality of second wavy struts 14 that extend in the axial direction from one end side to the other end side of the stent and are arranged in the circumferential direction of the stent, and the first wavy struts 13 and the second wavy struts 14 that are adjacent to each other. One or a plurality of connecting struts 15 that are connected and extend in a predetermined major axis direction are provided. The apex of the second wavy strut 14 is shifted by a predetermined length in the axial direction of the stent with respect to the apex of the first wavy strut 13 that is close to the circumferential direction of the stent 10 and curves in the same direction. . Further, the

end portions

13a and 13b of the first wavy strut 13 are coupled to the

end portions

14a and 14b of the adjacent second wavy struts.
The stent 10 of this embodiment is a so-called self-expanding stent that is formed in a substantially cylindrical shape, is compressed in the direction of the central axis when inserted into a living body, and expands outward when placed in the living body to restore the shape before compression. ing.

The first wavy strut 13 extends in the axial direction substantially parallel to the central axis of the stent. A plurality of first wavy struts 13 are arranged in the circumferential direction of the stent. The number of the first wavy struts 13 is preferably 3 or more, and more preferably about 3 to 8. Further, the plurality of first wavy struts 13 are preferably arranged so as to be substantially equiangular with respect to the central axis of the stent.
The second wavy strut 14 also extends in the axial direction substantially parallel to the central axis of the stent. A plurality of second wavy struts 14 are arranged in the circumferential direction of the stent, and each second wavy strut 14 is arranged between each first wavy strut. The number of the second wavy struts 14 is preferably 3 or more, particularly about 3 to 8. Furthermore, it is preferable that the plurality of second wavy struts 14 are arranged so as to be substantially equiangular with respect to the central axis of the stent. The number of second wavy struts 14 is the same as the number of first wavy struts.
The stent 10 includes one or a plurality of connection struts 15 that connect the adjacent first wavy struts 13 and second wavy struts 14 and extend in a predetermined major axis direction. In particular, in the stent 10 of this embodiment, the connection strut 15 has one end near the inflection point of one wavy strut, and the other end in a region slightly beyond the apex of the adjacent wavy strut. And extending in the axial direction and curved in the same direction as the apex of the other wavy strut. Specifically, as shown in FIG. 11, the connection strut 15 includes a curved first connection strut 15 a having a vertex directed toward one side in the circumferential direction of the stent 10 and a vertex directed toward the other circumferential side of the stent 10. And a curved second connection strut 15b. The connecting strut 15 is curved in an arc shape and has substantially the same radius as the arc of the curved portion of the first wavy strut 13 or the second wavy strut 14 that is close to the circumferential direction of the stent 10.

And the stent 10 of this Example is provided with the connection part 16 couple | bonded with the edge part of any 2nd waved strut which adjoins the one end side edge part and other end side edge part of all the 1st waved struts. . Specifically, one end 13a of the first wavy strut of the stent 10 is adjacent to one second wavy strut 14 (specifically, the second wavy strut located adjacent to the other side in the circumferential direction). 14) and an end portion 14 a on one end side and a connecting portion 16. Further, the other end 13b of the first wavy strut is the other end of the adjacent second wavy strut 14 (specifically, the second wavy strut 14 which is close and located on one side in the circumferential direction). The end portion 14 b on the side is coupled to the coupling portion 16. That is, the combination of the first wavy strut 13 and the second wavy strut 14 to be coupled is different (shifted one by one) in the coupling portion 16 on the one end side and the coupling portion 16 on the other end side.
And the radiopaque marker 17 is attached to the coupling | bond part 16 as shown in FIG. 10 thru | or FIG. In this embodiment, as shown in FIG. 12, the coupling portion 16 includes two

frame portions

16a and 16b extending in parallel at a predetermined distance in the end direction, and the radiopaque marker 17 includes: The two

frame portions

16a and 16b are encapsulated almost entirely or partially. The radiopaque marker 17 has a thin rectangular parallelepiped shape, and stores the two

frame portions

16a and 16b therein, and is fixed to the two

frame portions

16a and 16b by recessing the central portion. Has been. As a material for forming the radiopaque marker, one or two selected from the group of elements consisting of iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, and hafnium are used. More than one kind (alloy) can be preferably used.
Furthermore, the stent 10 is provided with a small hole 18 for inserting a stent proximal end portion fixing wire at each joint portion 16 on the proximal end side. The small hole 18 extends toward the center of the stent. In addition, it is preferable that the small hole 18 for inserting the wire for fixing the proximal end of the stent has a low friction inner surface or an easily removable form for enhancing the detachability of the wire 5. The low friction inner surface can be formed by making the inner surface a smooth surface or coating with a low friction material.

Moreover, as an easily detachable form of a small hole, what is shown in FIG. 15 can be considered. The small hole 18 formed in the coupling portion 16 shown in FIG. 15 has an opening edge of the small hole 18 whose diameter is chamfered or tapered. The small hole 18 may be such that the opening edge portions on both the outer surface side and the inner surface side of the stent are chamfered or tapered in diameter. This facilitates insertion and removal of the stent fixing wire.
As a constituent material of the stent 10, a super elastic metal is suitable. As the superelastic metal, a superelastic alloy is preferably used. The superelastic alloy here is generally called a shape memory alloy, and exhibits superelasticity at least at a living body temperature (around 37 ° C.). Particularly preferably, a Ti—Ni alloy of 49 to 53 atomic% Ni, a Cu—Zn alloy of 38.5 to 41.5 wt% Zn, a Cu—Zn—X alloy of 1 to 10 wt% X (X = Be, A superelastic metal body such as a Si—Sn, Al, Ga), Ni—Al alloy of 36 to 38 atomic% Al is preferably used. Particularly preferred is the Ti—Ni alloy described above. In addition, Ti—Ni—X alloy in which a part of Ti—Ni alloy is substituted with 0.01 to 10.0% X (X = Co, Fe, Mn, Cr, V, Al, Nb, W, B, etc.) Or a Ti—Ni—X alloy (X = Cu, Pb, Zr) in which a part of the Ti—Ni alloy is substituted with 0.01 to 30.0% atoms, and the cold work rate Alternatively, mechanical properties can be appropriately changed by selecting conditions for the final heat treatment. Further, the mechanical characteristics can be appropriately changed by selecting the cold work rate and / or the final heat treatment conditions using the Ti—Ni—X alloy. The buckling strength (yield stress during loading) of the superelastic alloy used is 5 to 200 kg / mm ² (22 ° C.), more preferably 8 to 150 kg / mm ^2. Restoring stress (yield stress during unloading) ) Is 3 to 180 kg / mm ² (22 ° C.), more preferably 5 to 130 kg / mm ² . Superelasticity here means that even if it is deformed (bending, pulling, compressing) to a region where normal metal is plastically deformed at the operating temperature, it will recover to its almost uncompressed shape without the need for heating after the deformation is released. It means to do.
The diameter of the stent when compressed is preferably about 0.5 to 1.8 mm, and more preferably 0.6 to 1.4 mm. Further, the length of the stent when not compressed is preferably about 5 to 200 mm, and particularly preferably 8.0 to 100.0 mm. Further, the uncompressed diameter of the stent is preferably about 1.5 to 6.0 mm, and more preferably 2.0 to 5.0 mm. Furthermore, the thickness of the stent is preferably about 0.05 to 0.40 mm, and particularly preferably 0.05 to 0.15 mm. The width of the wavy strut is preferably from 0.01 to 1.00 mm, particularly preferably from 0.05 to 0.2 mm. The surface of the wavy strut is preferably processed smoothly, and smoothing by electropolishing is more preferable. Further, the radial strength of the stent is preferably 0.1 to 30.0 N / cm, and particularly preferably 0.5 to 5.0 N / cm.

Next, the operation of the stent delivery system of the present invention will be described with reference to FIGS. 9 and 16 to 18.
When the entire stent 10 is housed in the sheath 2, the stent 10 is in the state shown in FIG. Then, by sliding the sheath 2 to the proximal end side, the stent 10 is exposed from the distal end opening of the sheath 2 as shown in FIG. The stent 10 exposed from the sheath 2 expands by a self-expanding force and tries to restore the form before compression. However, in this stent delivery system, since the proximal end portion of the stent 10 is anchored to the shaft portion 3 by the heat-breakable stent proximal end portion fixing wire 5, it cannot be expanded, and the state shown in FIG. 16 is obtained. When readjustment of the arrangement position of the stent 10 is necessary, the stent 10 can be re-stored in the sheath by sliding the sheath 2 in the distal direction. Then, after confirming that the stent 10 is disposed at the target site, by operating a power supply (not shown) connected to the shaft portion 3, The stent proximal end fixing wire 5 is broken. Thereby, the anchoring of the proximal end portion of the stent 10 by the heat-breakable stent proximal end portion fixing wire 5 is released, and the proximal end portion is also expanded as shown in FIG. Thereafter, by moving the stent delivery system 1 (sheath 2 and shaft portion 3) from which the stent has been released in the proximal direction, as shown in FIG. 18, the stent proximal end portion fixing wire that has anchored the stent 10. The middle part 5c of 5 is detached from the stent. In addition, since the one end of the fractured stent proximal end fixing wire 5 including the intermediate portion 5c is fixed to the shaft portion 3, it is neither released into the living body nor remains on the stent.

The stent delivery system of the present invention is as follows.
(1) A stent that is formed in a substantially cylindrical shape, is compressed in the direction of the central axis when inserted into a living body, and expands outward when placed in the living body and can be restored to its original shape before compression; a shaft portion having a guide wire lumen; And a stent delivery system in which the stent is housed in a distal end portion, and the stent is positioned near the distal end on the shaft portion, wherein the stent delivery system has one end and the other end on the shaft. A stent proximal end fixing wire fixed to the base and an intermediate portion anchored to the proximal end of the stent, and a fracture member for breaking the stent proximal end fixing wire and releasing the anchor of the stent A stent delivery system.
For this reason, since the base end portion is anchored to the shaft portion until the stent base end portion fixing wire is broken, the stent does not jump out when discharged from the sheath. In addition, even after the stent is discharged from the sheath, if the stent proximal end fixing wire is not broken, it can be re-stored in the sheath, and the position of the stent can be corrected. It can be reliably placed on the site.
Furthermore, if the wire for fixing the proximal end portion of the stent extends from the one end and the other end fixed to the shaft portion through the gap of the coil constituting the spring-like stopper and extends in the stent direction, the position of the wire Is stable, the fixation of the stent by the wire is ensured, and the detachment of the wire from the stent is also good.

And the following may be sufficient as the embodiment of this invention.
(2) The stent includes a plurality of small holes for insertion of the stent proximal end fixing wire provided in the proximal end in a substantially annular shape, and the intermediate portion of the stent proximal end fixing wire is The stent delivery system according to (1), wherein the plurality of small holes of the stent are annularly inserted.
(3) The stent includes a plurality of proximal-direction bent portions positioned at a proximal end portion, and the intermediate portion of the stent proximal-end fixing wire has an annular shape of the plurality of proximal-direction bent portions of the stent. The stent delivery system according to (1), which is inserted through the stent delivery system.
(4) The shaft portion includes a distal end tube having the guide wire lumen, and a shaft body having a distal end portion fixed to a proximal end side of the distal end tube, and the breaking member is disposed at the distal end portion of the shaft body. The stent delivery system according to any one of the above (1) to (3).
(5) The stent includes a distal end portion facing the distal end side of the sheath and a proximal end portion facing the proximal end side, and further has a bending free end protruding substantially at least on the proximal end side except for the proximal end portion. The exposure tip according to any one of (1) to (4) above, wherein the exposed tip is re-storable in the sheath by moving the sheath after the tip is exposed from the sheath. Stent delivery system.

(6) The stent proximal end fixing wire is a heat-breakable stent proximal end fixing wire, and the fracture member is a thermal fracture member according to any one of (1) to (5). Stent delivery system.
(7) The heat-breaking member includes a heat-generating portion for breaking, an electric cable having a distal end connected to the heat-generating portion and extending to a base end portion of the shaft body, the electric cable connected to the electric cable, and the shaft The stent delivery system according to (6), further including a connection portion with a power supply device formed at a proximal end portion of the main body.
(8) The shaft portion includes a proximal-side opening of a guide wire lumen that opens at a side portion proximal to the stent housing portion of the sheath, and the sheath is provided on the proximal side from the stent housing portion. The stent delivery system according to any one of (1) to (7), further comprising a sheath-side hole, and a guide wire can be inserted through the sheath-side hole and the proximal-end opening.
(9) The stent according to any one of (1) to (8), wherein the stent base end fixing wire breaks and the stent can be re-stored until the anchoring of the stent is released. Stent delivery system.
(10) The stent delivery system according to any one of (1) to (9), wherein the stent proximal end fixing wire is a thermoplastic resin fiber.

(11) The shaft portion includes a proximal-side stopper that is positioned near a proximal end of a portion where the stent is disposed and restricts movement of the stent in the proximal direction. The stent delivery system according to any one of 10).
(12) The stent delivery system according to (11), wherein the proximal end side stopper is a spring-like stopper wound around the shaft portion.
(13) The stent proximal end fixing wire extends from the one end and the other end fixed to the shaft through the gap of the coil constituting the spring-like stopper in the stent direction. The stent delivery system according to (12) above.
(14) The small hole for inserting the stent proximal end fixing wire of the stent has a low friction inner surface or an easily removable form for enhancing the detachability of the wire. The stent delivery system according to any one of 13).
(15) The stent according to any one of the above (1) to (14), wherein the apex of the proximal end side bent portion or the vicinity of the apex is bonded to another linear element, so that the stent does not have a free end. The stent delivery system according to 1.
(16) The stent connects the adjacent wavy struts extending in the axial direction from one end side to the other end side of the stent and arranged in the circumferential direction of the stent, and in a predetermined long axis direction. One or a plurality of connecting struts extending in the direction, and the end of the wavy strut is connected to the end of the adjacent wavy strut, according to any one of the above (1) to (15) Delivery system.
(17) The stent delivery system according to (16), wherein the connection strut is curved in an arc shape.
(18) The stent includes a coupling portion that couples end portions of one end side and the other end side of all the wavy struts to the end portions of the wavy struts adjacent to each other, and the coupling portion on the one end side and the other end side The stent delivery system according to the above (16) or (17), in which the combination of the wavy struts to be coupled is different in the coupling part.

Claims

A stent that is formed in a substantially cylindrical shape, is compressed in the direction of the central axis when inserted into a living body, and expands outward when placed in the living body and can be restored to its original shape before compression; a shaft portion having a guide wire lumen; and the stent And a stent delivery system in which the stent is located near the tip on the shaft portion,
The stent delivery system includes a stent proximal end fixing wire in which one end and the other end are fixed to the shaft portion, and an intermediate portion is anchored to the proximal end of the stent, and the stent proximal end fixing wire. A stent delivery system comprising: a breaking member for breaking the stent and releasing the anchoring of the stent.
The stent includes a plurality of small holes for inserting the stent proximal end fixing wire rod provided in the proximal end portion in a substantially annular shape, and the intermediate portion of the stent proximal end portion fixing wire includes the intermediate portion of the stent. The stent delivery system according to claim 1, wherein the plurality of small holes are inserted in an annular shape.
The stent includes a plurality of proximal-direction bent portions positioned at a proximal end portion, and the intermediate portion of the stent proximal-end fixing wire is annularly inserted through the plurality of proximal-direction bent portions of the stent. The stent delivery system according to claim 1.
The shaft portion includes a distal end tube having the guide wire lumen, and a shaft body having a distal end portion fixed to a proximal end side of the distal end tube, and the breaking member is provided at a distal end portion of the shaft body. The stent delivery system according to any one of claims 1 to 3.
The stent includes a distal end portion facing the distal end side of the sheath and a proximal end portion facing the proximal end side, and further has substantially no bending free end protruding at least on the proximal end side except the proximal end portion, The stent delivery system according to any one of claims 1 to 4, wherein the exposed distal end portion can be re-stored in the sheath by moving the sheath after the distal end portion is exposed from the sheath.
The stent delivery system according to any one of claims 1 to 5, wherein the stent proximal end fixing wire is a heat-breakable stent proximal end fixing wire, and the fracture member is a thermal fracture member.
The heat-breaking member includes a heat-generating portion for breaking, an electric cable having a distal end connected to the heat-generating portion and extending to a base end portion of the shaft main body, connected to the electric cable, and a base of the shaft main body. The stent delivery system according to claim 6, further comprising a connection portion with a power supply device formed at an end portion.
The shaft portion includes a proximal-side opening of a guide wire lumen that opens at a side portion proximal to the stent housing site of the sheath, and the sheath is a sheath provided proximal to the stent housing site. The stent delivery system according to any one of claims 1 to 7, further comprising a side hole, wherein a guide wire can be inserted from the sheath side hole and the proximal end side opening.
The stent delivery system according to any one of claims 1 to 8, wherein the stent is re-storable in the sheath until the stent proximal end fixing wire is broken and the anchoring of the stent is released.
The stent delivery system according to any one of claims 1 to 9, wherein the stent proximal end fixing wire is a thermoplastic resin fiber.
11. The shaft according to claim 1, further comprising a proximal-side stopper that is positioned near a proximal end of a portion where the stent is disposed and that restricts movement of the stent in the proximal direction. The stent delivery system as described.
The stent delivery system according to claim 11, wherein the proximal-side stopper is a spring-like stopper wound around the shaft portion.
The stent proximal end fixing wire extends from the one end and the other end fixed to the shaft portion through a coil gap constituting the spring-like stopper in the stent direction. Item 13. The stent delivery system according to Item 12.
The small hole for inserting the stent proximal end portion fixing wire of the stent has a low friction inner surface or an easily removable form for enhancing the detachability of the wire. The stent delivery system as described.
The stent delivery system according to any one of claims 1 to 14, wherein the stent has no free end by coupling the apex of the bent portion on the base end side or the vicinity of the apex with another linear element. .
The stent extends in the axial direction from one end side to the other end side of the stent and connects a plurality of wavy struts arranged in the circumferential direction of the stent to the adjacent wavy struts and extends in a predetermined major axis direction. The stent delivery system according to any one of claims 1 to 15, further comprising one or a plurality of connecting struts, and further, an end portion of the wavy strut is coupled to an end portion of an adjacent wavy strut.
The stent delivery system according to claim 16, wherein the connecting strut is curved in an arc shape.
The stent includes a coupling portion that couples one end side and the other end side end of each of the wavy struts to the end portion of the wavy struts adjacent to each other, and the one end side coupling portion and the other end side coupling portion. The stent delivery system according to claim 16 or 17, wherein the combination of the wavy struts to be combined is different.